Local Anaesthetic Properties vs. Neurotoxicity for (+)- and (−)-Carvone: An Ex Vivo Electrophysiological Study

Abstract

!The two carvone enantiomers were tested for local anaesthetic activity at concentrations of 10 and 20 mM using a nerve preparation based on the isolated sciatic nerve of the frog and were found to induce similar responses. They eliminated the evoked compound action potential within 6-7 min, while there was an instant 83 to 87% recovery when they were washed out from the nerve preparation and replaced with normal saline. Both carvones have the same pattern of action as 10 mM lidocaine, the standard local anaesthetic, but they are 3-4 times less active with respect to the time of response. When the nerves were exposed to the carvones for a period of time longer than 6-7 min, for example 1 h, there was no recovery at all of the evoked compound action potential, indicating a neurotoxic action. In contrast, when nerves were exposed under the same conditions to lidocaine and another natural compound with local anaesthetic properties, 2-heptanone, there was an 80-100% recovery. This unusual neurotoxic effect of (+)-and (−)-carvone can be a disadvantage for their use in clinical practice.

Health Benefits and Pharmacological Properties of Carvone

“…Several authors have attempted to study the effect of the use of carvone on some neurological disorders such as depression, sedation, nociception, seizure, local anesthesia, as well as its effect on some receptors and on the action potential [ 9 , 10 , 11 , 12 ]. To study these effects, different models are used such as Swiss mice [ 9 ], Wistar rats [ 11 ], frog’s sciatic nerve [ 10 ], and cortical neurons prepared from the cerebral cortices of rat fetuses [ 12 ] ( Table 1 ).…”

“…Faliagkas et al [ 10 ] tested two enantiomers of carvone ((+)- and (−)-carvone) for their local anesthetic activity at two concentrations, 10 and 20 mM. The authors used a nerve preparation based on the frog’s sciatic nerve.…”

“…Several authors have attempted to study the effect of the use of carvone on some neurological disorders such as depression, sedation, nociception, seizure, local anesthesia, as well as its effect on some receptors and on the action potential [9][10][11][12]. To study these effects, different models are used such as Swiss mice [9], Wistar rats [11], frog's sciatic nerve [10], and cortical neurons prepared from the cerebral cortices of rat fetuses [12] (Table 1). were not lethal The insecticidal effect of carvones can be explained by their interaction with the GABAA receptor at its non-competitive blocker region [12] To assess the effect of carvone on disorders related to the central nervous system (depression, convulsion), De Sousa et al [9] conducted their study using different enantiomers of carvone ((S)-(+)-carvone and (R)-(−)-carvone).…”

“…Currently, many studies have proven that carvone has promising pharmacological properties. Indeed, it has shown neuroprotective effects, and can therefore be developed as a drug against certain disorders such as depression, sedation, nociception, and seizure [ 9 , 10 , 11 , 12 ]. This molecule has also demonstrated an antidiabetic effect, through its role in the prevention of obesity and metabolic problems associated with high-fat diets, achieved by improving glycoprotein component abnormalities and controlling glucose metabolism [ 13 , 14 , 15 ].…”

Effect of Drying Method and Storage Days on Essential Oil Yield and Quality of Rue (Ruta Chalepensis) leaves

“…Essential oils are components of herbs and plants which are rich in hydrocarbon compounds that have oxygenated, hydrogenated, and dehydrogenated functional groups [1,2]. Essential oils of plant origin are an important product of agriculture-based industries and have various applications, mainly in food preservation and as flavoring agents in food products, drinks, perfumeries, cosmetics, and medicines particularly as analgesics, anti-inflammatory, antispasmodic, local anesthetic, anthelmintic, antipruritic, and antiseptic as well as many other therapeutic uses [3][4][5][6]. At present, there is a growing interest in essential oils and their components, particularly for their broad-spectrum antimicrobial activity, which can provide, for instance, alternative functional ingredients to extend the shelf life of food products and ensure microbial safety for consumers [7].…”